The Polish version of the Process-Based Assessment Tool (PBAT)-The measure of processes of change in psychological interventions.

The aim of this study was to conduct a Polish adaptation of Process-Based Assessment Tool (PBAT), to be used primarily for measurement of the processes of change occurring within psychological interventions, regardless of the therapeutic approach. PBAT includes a set of statements related to negative and positive behaviors in the domains of selection, variation, and retention, as it is theoretically embedded in the evolutionary approach. The tool's construction was determined by resolving the issue of ergodic error, hence employs an idiographic approach. A total of 602 (319 F, 281 M) participants in the age 18-85 took part in the study. Apart from the original 21 PBAT items, two additional items related to self-care vs. self-impatience were tested. The included criterion variables related to the assessment of individual functioning in terms of distress (sadness, anxiety, stress, anger, lack of social support), health (health and vitality levels), the fulfillment or frustration of autonomy, connection, and competence need, as well as well-being (life-satisfaction and sense of professional burnout). The machine learning Boruta algorithm was utilized. PBAT items significantly predicted criterion variables. Positive selection behaviors were strongest predictors of Health, Vitality, Life-satisfaction as well as satisfaction of autonomy, connection and competence needs. Negative selection behaviors were strongest predictors of distress, lack of social support, work burnout as well as the frustration of autonomy, connection and competence needs. Overall, the PBAT items were more predictive of variables encompassing negative aspects of functioning than positive aspects or well-being. The overall relationships and conclusions are consistent with those obtained in the original study. The Polish version of PBAT is recommended for use in further scientific research and therapeutic processes.